US 2004/0062179 describes an optical disc recording apparatus capable of forming a visually detectable pattern on an optical disc. The visually detectable pattern comprises for example a logo, a sequence of characters or a combination thereof. The visually detectable pattern is printed at a resolution suitable for detection by the human visual system. For example the visually detectable pattern may be printed at a resolution of 1 to several hundred dots per mm2 (as compared to computer readable data, which is stored at the record carrier at a resolution in the order of several Mbits/mm2) In this way a user does not need a reading device to recognize the contents of the optical disk. A simple visual inspection suffices.
In general, data recordings on optical discs start at a certain radius at the central part of the disc and follow a groove that spirals outwards. With optical disc types such as CD and DVD, the specifications require in most cases that the data is contiguously recorded between a start and an end of the data recording (this is to ensure playability in Read-Only devices). Existing recording apparatuses that are able to print a visually detectable pattern to the disc, will therefore print this pattern at a radius outside the recorded data. The disadvantages of that location are:                (1) A visually detectable pattern with a certain radial width occupies more storage space at the peripheral portion of a disc than at a more central portion of the disc;        (2) It is not possible to append data without destroying the original visually detectable pattern; and        (3) The visually detectable pattern is a feature that is not standardized in common optical disc system standards. The area comprising the visually detectable pattern contains data that is not interpretable by devices according to the optical disc system standards. Very likely, no tracking signals, such as DPD or push pull signals, for servo control are generated when the read head accesses this area. The absence of tracking signals might cause unwanted compatibility problems with legacy drives. To maintain the exchange-compatibility of a recorded disc containing the visually detectable pattern with other drives that only expect machine-readable data (non-aware drives) it is desired that        The effects of the visually detectable pattern do not impede normal players and drives for the record carrier;        Read access of the area with the visually detectable pattern is minimized; and        An area containing a visually detectable pattern is not unintentionally overwritten with new data.        
The apparatus described in US 2004/0062179 arranges the visually detectable pattern at the periphery of the disc. This position of the visually detectable pattern however has the disadvantage that it occupies a relatively large area. As a result the data storage capacity of the disc is substantially reduced.